Discuss, don't ban, climate change film

Joe Nation

Published
4:00 am PST, Friday, March 2, 2007

Across the pond in the United Kingdom, the Environment and Education ministers announced in early January that they are sending 4,000 copies of Al Gore's Oscar-winning documentary, "An Inconvenient Truth," to British secondary schools. Meanwhile, in the United States, we seem to be moving in the opposite direction.

In Washington state, the Federal Way school board recently imposed a "moratorium" on (i.e., banned) the showing of the film. Not to be outdone, the school board in Yakima, Wash., also prevented the school's environmental club from showing the film.

How did global warming get wrapped up in school board politics? In the case of Federal Way, the school board received "a half dozen" complaints from parents, including one who believes the Earth is 14,000 years old (and who apparently has not seen the film). Here's the school board's official explanation: "An Inconvenient Truth" is controversial and demonstrates bias. Therefore, any teacher who wants to show the movie must secure the approval of the principal and superintendent and, according to policy, must also present additional information and perspectives to balance those biases."

Where is that additional information and perspective? Certainly not found among most of the scientists who study climate change and who issued their latest United Nations' report on climate change one month ago.

Uncertainty does indeed exist about the theory of global warming, but only around the edges. Does the Gore movie misrepresent the science? It appears that he does not. Just as the film was making its debut, the Associated Press surveyed 19 top climate researchers and asked if he had portrayed the science correctly. All 19 agreed that he had, indeed, gotten the science right.

So what about the science itself? Is it controversial and subject to bias? Here's what the latest U.N. report, written by more than 2,000 scientists and reviewers, concludes: The likelihood that the observed increase in average global temperatures is due to anthropogenic (i.e., man-made) factors is between 90 and 99 percent. The 2001 U.N. report put that likelihood at between 66 and 90 percent.

The chance that climate change is occurring without "external forcings," i.e, human factors, is less than 1 percent.

The anticipated increase in average global temperature by the year 2100 is between 1.8 and 4.0 degrees Celsius (2.9 -7.2 degrees Fahrenheit) with a likely increase of about 3 degrees Celsius (4.8 degrees Fahrenheit). This compares with a 2001 forecast of 1.4-5.8 degrees Celsius and a 1997 forecast of 1.0 to 3.5 degrees Celsius.

Sea levels are likely to rise 0.3 to 0.9 meters (a maximum of about 3 feet) by 2100, compared with a 2001 forecast rise of 0.09 to 0.88 meters.

In short, the 2007 U.N. report is more confident than in its 2001 findings, and it is more precise in its forecasts about temperature and sea-level increases. If there was bias in earlier climate change science, it is that it understated the likelihood and potential consequences from global warming.

Which questions remain? There really aren't many, except in relatively minor areas. The 2007 U.N. report notes that there has been surprisingly no change in Antarctic sea ice. Extra-tropical storm frequency and intensity have not changed, and there has been no change in diurnal (warmest minus coolest) temperatures. And yes, the latest U.N. report says that Greenland is unlikely to melt completely for 1,000 years, which would lead to a 20-foot rise in sea levels, but only if temperatures increase more than currently anticipated. But the basic science about the causes of climate change, greenhouse-gas accumulation in the atmosphere, and the general effects is indisputable. What we really don't know is how severe the consequences will be.

School boards should not hesitate to allow all perspectives to be included in debate over climate change. In theory -- and in practice -- schools are where we should encourage students to analyze and debate controversial issues. Banning "An Inconvenient Truth," and the science that supports it, doesn't advance knowledge and understanding. What it does is continue to politicize a subject where science should dominate.

For my part, I would encourage school boards to present all perspectives, including those of the 2,000 scientists and reviewers worldwide who present a very grim picture on climate change, and that of the parents and school board members who argue that the Earth is only 14,000 years old and deny that that climate change is occurring. As a teacher, I'm comfortable that students will see the truth.